public void adding_an_item_updates_the_minimum_if_it_has_changed()
{
var model = new DoubleCollectionModel();
var observer = model.CreateObserver();
for(double item = 5d; item > -5d; --item)
{
model.Add(item);
Assert.Equal(item, model.Minimum);
model.Add(item + 1);
Assert.Equal(item, model.Minimum);
}
Assert.Equal(10, observer.GetChangeCount(x => x.Minimum));
}